Google+ Circles can be Shared Publicly

I mainly use Google Plus to connect with close friends from school and follow some very influential bloggers and tech enthusiasts. Being a blogger, I have a Google+ Circle where I have added many Google employees. This is mainly to stay updated on what is new from Google.
Google+ has introduced a feature which allows sharing of Circles. Just look up your Google+ Circles and click on it to see new option for sharing it.

A user can share this Circle with a single friend, other Circles or even publicly.

Why Google+ Circle Sharing is significant?

Usually being social is about having groups with similar interests interact with each other a lot. One to one sharing is fine but not as socially significant. I mean we can share one to one via email too. 
The part of sharing circles makes sense as people accepting these Circles can also edit it further by adding or removing certain accounts. Considering , it will now have to add a lot of features to make sure it keeps attracting a decent number of people.
Also with , Google+ will surely need more innovation, like sharing of circles to compete well.
I wonder if allowing a search feature for looking up publicly shared Circles would be a great idea. Do drop in your comments and views.